Improved bridge



Halimi l,diurni Meeuw ROBERT vW. ROGERS, OF P ITTSBURG, PENNSYLVANIA.

Letters PatentNo. 85,332, dated December" 29, 1868.

The Schedule referred to in these. Letters Patent and making parc of the same.

To all whom it may concern Be it known that I, ROBERT W. Roenes, of Pittsburg, in the county of Allegheny, and State of Pennsylvania, have invented a new and useful Improvement in Bridges; and I do hereby declare that the following is a fulland exact description thereof, reference being hadto the accompanying drawings, and to the letters and figures of reference marked thereon.

The ynature of my invention consists in the construction and arrangement .of bridges in sections, when supported, arranged, and connected together in the manner hereinafter described.

To enable others skilled in lthe art to make and use my invention, I will proceed to describe its construction and operation.

In the accompanying drawings, which form part of my specification- Figure l is an end elevation of my improvement in bridges.

Figure 2 is a longitudinal section of the same, when cut through at line y of lig. 1.

Figure 3 is a longitudinal section of the same, when out through at line y oirfig. 1.

Figures Aand 5. represent side elevations of two similar sections of a span'in the bridge.

Figure 6 is a top view of a section ofthe strainingrods or links, and represents the manner of keying up the rods or links, and the method of securing the keys in the desired position. I

In the drawings- A represents the abutment, and

P represents a pier of the bridge.

The abutments and piers are constructed ofordinary masonry-work.

B represents the sections, which are secured on and to what is termed a pier-plate, which should be secured to' the abutment A' in a very strong and secure the dividing lines between the sections should converge to a common centre, which should be theV centre of a circle, an are of which should form a span of the bridge, as shown in tig. 2.

The sections C aresecured together by means oi' bolts, as indicated at the points marked 1. v

- One' endof each span of they bridge is secured to what are termed expansion-plates, which rest on pier-plates, m, and' so arranged that they will move or slide back or forward 'on the pier-plates m, on a linel with the longitudinal plane of the bridge, to allow for the expansion of the several parts, and of the whole, as combined in a single span.

The end of the next span is secured firmly on and to the plates fm, and its other end being provided with expansion-plates n, rests on plates m on the next pier, and thus each span of the bridge is arranged with one lend secured firmly and in a xed position, and the other en d arranged so that it can slide back and forward suil'iciently to' allow for the expansion of the several parts.

B represents the cross-beams for the tloor f. These beams are bolted to the sides of the bridge, as shown in tig. 2, and should rest on suitable projections.

' D are cross-ties or braces, for. holding the upper part of the sides of the bridge in position,

e represents the foot-walks ofthe bridge.

x represents rails, for railways on the bridge.

In recesses in the door j, directly under the rails x, are placed spiral springs, 5, en which rests the bottom or base of the rails. These springs vare used 'for the purpose4 of relieving the bridge from the siibrations caused by the ears passing over the rails x.

The links or rods, marked 2, are usedl for the purpose of tying and binding together, longitudinally, the several parts and spans of the bridge, and also forimparting strength and firmness to the structure, as a whole.

The several links orrods are connected and drawn up, so as to obtain t'hedesired tension'ou the links/or rods 2, by means of keys, 3. The construction and arrangement of the links or rods 2 and keys 3 are clearly shown in gs. 1, 3, and 6.

As the construction and arrangement of the several parts of my improvement in bridges will readily be seen and understood from the foregoing description, and by reference to the accompanying/drawings, I will therefore, without further description of its construction, proceed to set forth some few ofthe many 'advantages of my improvement in bridges.

First, it is a very cheap method of constructing what are termed iron bridges, for I avoid the use of angle blocks, suspension-blocks, counter-rods and top-cords," all of which are items in the construction of bridges which add greatly to their cost of construction.

Second, the form of the several sections of my improvement in bridges being an arc of a circle, and

each span also an arc, it will readily be seen'that its sustaining-power willbe very great, and that this mode of constructing bridges is very desirable for strength and durability.

Third, by making each section hollow, each side of the bridge can be made into a series of roomsor com-v partments, i'or stores, oihces, or dwellings.

Fourth, in case of any accident which would impair any part of. the bridge, the injured part canbe easily and readily repaired.

Fifth, my method of constructing 4,bridges canbe adapted to deck or through-bridges.

Having thus described the nature, construction, and advantages of my improvement in bridges,

What I claim as of my invention, is

The construction and 'arrangement of bridges in' sections, when supported, arranged, and'connected together in the manner and for the purpose herein described.

,ROB'lH W,.ROGERS. Witnesses:

A. C. JOHNSTON, JAMES THOMPSON. 

